The present invention relates to a reflective solar tracking system for reflecting light rays from the sun onto a solar energy collector. The system tracks the sun as it moves across the sky so that light rays are always reflected onto the collector.
One reflective-type solar tracking system is shown in U.S. Pat. No. 4,063,543 of Hedger. In this system a major reflector is mounted so as to be movable in both a North/South and East/West direction. The motion is controlled by the reflection of light rays from the reflector onto a position-detecting target via a second, minor reflector. When the rays are reflected onto a neutral position on the target, the major reflector is positioned to direct light rays onto the collector. When the rays are reflected off the neutral position, the major reflector is repositioned on one or both directions until light rays are again directed onto the collector.
There have been many servo control tracking devices in solar energy collection devices in the prior art. Many however, are applied to systems that move the entire collector array rather than a reflector device for a remote target which offers the advantage of the light weight, mobility and low power requirements to operate the moving reflective parts while the heavier collector array can remain stationary. An example of such a device where the whole collector array is movable is Russell U.S. Pat. No. 4,290,411. The advantages of a fixed collector and a movable reflector have been recognized before in such art as Hedger which involves an additional aiming reflective subsystem. Such systems suffer from alignment difficulties which can disturb the tracking function and because in Hedger alignment of the main reflector and the subsystem aiming reflector involve two alignments, the problem is compounded. The present invention seeks to reduce alignment errors by improvement of system rigidity, simplification of the tracking computation, and operability through any range of sun positioning without major intervention or adjustment.